Apparatus for feeding sheets,blanks and the like

ABSTRACT

An apparatus used for feeding sheets, blanks and the like from beneath a pile into a converting or processing machine, particularly a machine for making envelopes and the like, includes a middle rocking sucker engaging the bottom sheet of a pile and side suckers which rock along with the middle sucker. The apparatus is particularly characterized in that a separate control member is provided for the side suckers. This control member controls the start of the suction of the side suckers with a time delay with respect to the start of suction of the middle sucker and causes the suction of the side suckers to end simultaneously with the end of suction of the middle sucker.

United States Patent I (72) lmentors Gunter Ehlscheid [56] References Cited Niederbieber: UNITED STATES PATENTS Ernst Meess. Neuwied, both of. Germany 3 I72 655 3/1965 Lenk 271/29 211 ApplNo 364.014 Filed 0&61969 3,380,353 4/1968 Mittermager 271/29X [45] Patented June 22, 1971 Primary Examiner-Joseph Wegbreit [73] Assignee Winkler & Dunnebier Maschinenfabrik AlwrneyRichards a Ge und Eisengiesserei K.G. Neuwied am Rhine, Germany NOV-16,1968 ABSTRACT: An apparatus used for feeding sheets, blanks l l Germany and the like from beneath a pile into a converting or l l P 09 376-0 processing machine, particularly a machine for making envelopes and the like, includes a middle rocking sucker engaging the bottom sheet of a pile and side suckers which rock [Sill FEEDING SHEETS BLANKS along with the middle sucker. The apparatus is particularly 4 Cl 7D characterized in that a separate control member is provided aims rawmg for the side suckers. This control member controls the start of [52] US. Cl 271/29 the suction of the side suckers with a time delay with respect [5 l 1 Int. Cl B65h 3/08 to the start of suction of the middle sucker and causes the suc- [50] Field of Search 271 I29, 23, tion of the side suckers to end simultaneously with the end of 32, 19, 2 suction of the middle sucker.

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ATTorLNss5 APPARATUS FOR FEEDING SHEETS, BLANKS AND THE LIKE This invention relates to an apparatus for individually feeding sheets, envelope blanks and the like (hereinafter referred to as sheets) made of paper or other suitable material from beneath a pile of such sheets.

German Pat. No. 537,189 describes an apparatus of this type in which a rocking sucker engaging the bottom sheet of the pile near its front edge and connected to or separated from a suction air pipe in time with its rocking movements cooperates with rotating feed segments in order to feed each sheet brought by the sucker into the region of the feed segments, into a processing machine from beneath a pile of sheets.

German Pat. No. 836,431 describes additionally that pile supports may be located laterally beside the sucker and caused to carry out a rocking movement. The remainder of the pile situated above the bottom sheet is then supported beneath its front edge while the bottom sheet is guided downwardly by the rocking sucker. The same patent describes the rocking pile supports as consisting of blower nozzles which just before the beginning of the withdrawal of the bottom sheet by the feed segments blow controlled air between the bottom sheet and the next sheet situated thereabove in order to prevent the sheet above the bottom sheet from being entrained.

German Pat. No. 1,238,319 describes additionally a tongue which rocks above the sucker in time therewith and which penetrates into the gap formed by the sucker between the bottom sheet which is bent down at its front edge, and the next sheet thereabove, and holds back the latter sheet on the subsequent downward movement of the sucker with the sheet attached thereto. This construction ensures that the rocking sucker will supply only a single sheet to the feed segments.

Finally, German Pat. specification No 1,270,941 describes a construction wherein the suction nozzle of the sucker is hollowed out at its top side contacting the sheet, so that the bottom sheet is drawn into this cavity of the suction nozzle during the suction operation. This prevents the rocking sucker from bending simultaneously two sheets downwardly at their front edges and supplying them both together to the feed segments. Blanks for envelopes or the like, which frequently adhere to one another at their cut edges are reliably separated by a hollowed suction nozzle of this type, and it is not possible to obtain this effect reliably simply by bending the sheets downwards with a sucker having a flat suction nozzle.

Known systems of this kind for feeding narrow sheets or blanks for envelopes or the like are usually provided with a single rocking sucker and a rocking tongue, two pile supports in the form of blower nozzles which are arranged to rock laterally of the tongue, and two feed segments. lf wide sheets are to be fed, additional rocking suckers each having its as sociated rocking tongue are frequently provided beside the middle sucker and near the sheet side edges The provision of a plurality of rocking suckers each having a suction nozzle hollowed out for reliably separating'the bottom sheet has a disadvantage, however. When a sheet of paper is drawn near its end into the cavity of a suction nozzle, it slips from both sides in accordance with the greater length of the are as compared with the length of its chord towards the center of the suction nozzle. This slipping movement is rendered difficult if not impossible by arranging additional suckers to act on the same sheet at the same time beside the sucker. The formation of an adequate gap between the bottom sheet and the next sheet thereabove is no longer assured. The tongue which should penetrate into the gap above the bottom sheet may engage beneath the bottom sheet and the feed no longer operates satisfactorily. Alternately, when a plurality of rocking suckers are provided with flat suction nozzles and each with an associated rocking tongue, there is a risk that two or more sheets catching at their front edge may be bent away by one or more of the suckers and pass beneath the tongue of the associated sucker. if this happens uniformly at all the suckers, a number of sheets are fed simultaneously. If one sucker bends away just one sheet, while the others bend away two sheets, or if just one sucker bends away two or more sheets, the sheets above the bottom sheet become torn. In either case, malfunctioning occurs.

An object of the present invention is to eliminate the drawbacks of prior art devices.

Other objects of the present invention will become apparent in the course of the following specification.

In the accomplishment of the objectives of the present invention it was found desirable to provide an apparatus comprising a plate bearing or supporting a pile of sheets, a rocking sucker which engages the bottom sheet of the pile approximately in the middle and near its front edge projecting beyond the plate, said sucker being periodically connected to or separated from a suction air pipe, and comprising a suction nozzle which is hollowed out at its top which contacts the sheet, a tongue which rocks in time with the sucker and penetrates into the gap formed by the sucker between the bottom sheet and the next sheet situated thereabove, rocking pile supports constructed as blower nozzles and disposed laterally beside the sucker and the tongue, rotating feed segments for drawing the sheet brought into the range thereof by the sucker from beneath the pile, and additional suckers, each disposed on one side of the middle rocking sucker and rocking in time therewith and engaging beneath the bottom sheet, whereby a separate control member is provided for the side suckers and controls the start of the suction of the side suckers with a time delay with respect to the start of the suction of the middle sucker, and controls the end of the suction of the lateral suckers simultaneously with respect to the end of the suction of the middle sucker.

In the apparatus accordingto the present invention, only the middle rocking sucker whose suction nozzle is hollowed out at its top contacting the bottom sheet has associated with it a tongue rocking in time therewith for separating the sheet drawn into the suction nozzle cavity from the net sheet thereabove. The lateral rocking suckers have no such tongues associated with them. They contact the bottom sheet only lightly near its front edge. Since their suction operation begins after the suction of the middle sucker, the bottom sheet can be sucked without obstruction into the cavity of the suction nozzle of the middle rocking sucker. The actual separation of the bottom sheet from the part of the pile thereabove is thus carried out solely by the middle rocking sucker and its associated rocking tongue.

The elimination of the tongues above the lateral rocking suckers makes the system much easier to adjust and does away with any possibility of malfunctioning. Even if the lateral rocking suckers bend away more than one sheet at its front edge, only a single sheet is engaged by the feed segments and fed from beneath the pile.

According to the present'invention, in order to ensure still further that the bottom sheet is separated from the next sheet thereabove, the middle rocking sucker and its associated rocking tongue may have a stationary blower nozzle associated therewith, such nozzle blowing air for a short period into the gap above the bottom sheet formed by the suction nozzle, the blown air being controlled in time with the rocking sucker, so that the sheet above the bottom sheet is forced upwardly. One and the same rotary valve is advantageously used as the control member for this blown air and for the suction air for the lateral rocking suckers.

The system according to the present invention is particularly suitable for feeding blanks for relatively wide envelopes, in which the flap situated at the front in the direction of feed is recessed in the center and hence recedes with respect to the lateral parts of the front edge. It was hitherto very difficult to feed such blanks with known systems and these difficulties are eliminated by the system according to the present invention.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings, showing, by way of example only, a preferred embodiment of the inventive ides.

In the drawings:

FIG. 1 is a section through the apparatus of the present invention along the line ll-I-I in FIG. 2 at the start of the downward movement of the rocking suckers;

FIG. 2 is a section through the apparatus along the line ll-ll in FIG. 1;

FIG. 3 is a section through the apparatus similar to that of FIG. 1, but illustrates the apparatus at the end of the downward movement of the rocking suckers;

FIG. 4 is a longitudinal section through the common control member for the blown air and the suction air;

FIG. 5 is a side elevation of the control member for the blown air and the suction air in the direction of the arrow A in FIG. 4;

FIG. 6 is a longitudinal section through the suction nozzle of the middle sucker on an enlarged scale; and

FIG. 7 is a section through the middle sucker along the line VII-VII in FIG. 6.

The apparatus shown in FIGS. l-3 includes a plate 1 which carries a pile of sheets S and the front edge 1 of which is bent downwardly. The pile S projecting beyond the front edge 1' of the plate is held in the correct position by stops 3. Cross members 2 fixed to the plate 1 secure it to the machine sidewalls 4. A shaft 5 with feed segments 6 secured thereto is mounted rotatably in the machine sidewalls. Rubber rollers 8 are mounted on a shaft 7 and cooperate with feed segments 6. A hollow shaft 9, to which a central sucker 10 and two lateral suckers 11 are secured, a hollow shaft 12 to which two pile supports 13 are secured, and a shaft 14 which, like the shaft 5, carries exactly one revolution per cycle for feeding a sheet from beneath the pile of sheets S, are mounted rotatably in the sidewalls 4. A retainer 15 for a tongue 16 is rotatably mounted on the shaft 12 and is controlled by a rod or bar 15 independently of the angular rotation of the shaft 12. The shafts 9 and 12, and the tongue 16 are intermittently vibrated or oscillated in known manner (not shown) by cams or the like rotating in time with the feed.

The middle sucker 10 has a suction nozzle 17 which is hollowed out at the top and which has suction apertures 18 receiving suction air through the hollow shaft 17 and a longitudinal bore 20 in the shaft 9, the suction air being controlled in time with the feed.

Each of the side suckers 11 has a suction nozzle 21 with a suction aperture 22. Their retainers 23 are also clamped on the shaft 9. The side suckers and their suction apertures 22 receive suction air through hoses 24 and a control member 25 rotating with the shaft 14, the air being controlled in time with the feed, the air supply being independent of the air supply to the sucker 10.

Each of the pile supports 13 has a shoe 26 which engages beneath the pile S and which has an air slot 27. The supports are mounted rigidly in retainers 28 secured to the shaft 112 and receive blown air through a longitudinal bore 29 in the shaft 12, the air being controlled in time with the feed and penetrating, when the pile supports are in the position shown in FIG. 3, through the air slot 27 between the sheet B drawn down by the oscillating suckers 10, 11, and the part of the pile situated above the sheet B.

Above the tongue 16 and at an angle of about 30 to the plate 1, a stationary blower nozzle 30 is located and is secured in a manner not shown. The blower 30 is slightly spaced from the front bottom edge of the pile of sheets S, so that it blows air exactly into the gap between the bottom sheet of the pile sucked up by the suction nozzle 17 of the middle rocking sucker 10 and the net sheet situated thereabove, before the tip of the tongue 16 penetrates into the gap. The blower 30 is connected to the control member 25 by a hose 31.

As best shown in FIGS. 4 and 5, the control member 25 comprises a rotating disc 32 which is secured against rotation on the shaft 14 by a screw 33, and two nonrotating side parts 34, 35 rotatably mounted on the shaft 14 and secured against longitudinal displacement thereon by rings 36. Each of the two side parts 34, 35 has a forked stop 37 with longitudinal slots 37 for fixing screws 38, which engages over a bolt 45 secured in the sidewall 4 and prevents the side parts 34, 35 from moving with the shaft 14.

Two ducts 39, 40 are provided in the flat side of the side part 34 adjacent the disc 32; they have the shape of arcs of a circle and are situated on the same radius. Opposite them are corresponding ducts 39, 40' in the flat side of the side part 35. Spigots 41, 41 lead from outside into the ducts 39, 39', respectively, which are used to control the suction air of the rocking side suckers 11, while spigots 42, 42 lead into the ducts 40, 40, respectively, which are used to control the blown air of the blower nozzle 30. Spigot 41 is connected by hose 43 to the machine suction line, while spigot 41 is connected by two hoses 24 to the two side suckers 11. Spigot 42 is connected by a hose 50 to the machine blown air line, while spigot 41 is connected by hose 31 to the blower nozzle 30.

The disc 32 rotating with the shaft 14 is provided with an aperture 44 which alternately interconnects the registering air ducts 39, 39 and 40, 40 respectively, for as long as it registers with these air ducts on rotation of the disc 32. The lengths of the arcs of these air ducts correspond to the required suction time for the side rocking suckers 11 and the blowing time of the blower nozzle 30. A slot 46 is provided in the side part 35 just after the rear end of the air duct 39 as considered in the direction of rotation of the disc 32; the slot 46 leads outwards and through it air from the exterior flows for a short time into the air duct 39 through the aperture 44 in the rotating disc 32, so that the suckers l 1 release the sucked-in sheet. The control member (not shown) for the middle rocking sucker 10 is advantageously constructed in the same manner. Displacement of the forked stops 37 in the region of the slots 37 after the screws 38 have been released, provides an accurate adjustment of the time when the suction of the suckers l 1 starts with respect to the time when the suction of the middle sucker starts.

Starting from the position of the system shown in FIG. 1, in which all three rocking suckers 10, 11 are stationary with their suction nozzles contacting the bottom sheet B of the pile S, a full working cycle of the system comprises the following stages:

a. Only the middle sucker 10 is operative and sucks the bottom sheet B near its front edge into the cavity 47 of its suction noule 17 (see FIGS. 6 and 7). At the same time, the blower nozzle 30 receives blown air through the air ducts 40, 40 and assists in forming a gap between the bottom sheet B and the net sheet thereabove.

b. The tongue 16 pivots into the gap between the bottom sheet and the next sheet thereabove and thus separates the bottom sheet from the remainder of the pile. The blower nozzle 30 is separated from the blown air supply by the control element 25.

c. The suckers 11 which are still in their position shown in FIG. ll, receive suction air through the air ducts 39, 39' and also suck the bottom sheet B with a time delay. The downward movement of the suckers 10, 11, together with the bottom sheet held by them, then starts.

d. The shoes 26 of the pile supports 13 rock over the sheet B moved down by the suckers 10, 11, and beneath the remainder of the pile S situated above the sheet B. Just before the suckers 10, ll reach their lowermost position (see FIG. 3), the pile supports begin to blow air between the bottom sheet B and the remainder of the pile S situated thereabove.

e. After reaching their lowermost position, the rocking suckers l0, 11 are simultaneously separated from the suction air pipe. The feed segments 6 take over the sheet B which has been brought into their range by the rocking suckers, and draw it, in cooperation with the rollers 8, around the rounded front edge 1 of the plate 1 beneath the pile, while the pile supports 13 blow air. The feed segments 6 engage the sheet B near its front end first of all by their engagement edge 47 which presses against the rollers 8, and as they continue to rotate they hold it by suction apertures 48 which receive periodically controlled suction air through a longitudinal bore 49 in the shaft 5. The feed segments 6 then pass the sheet to a following roller (not shown) of the processing or converting machine.

f. All the parts of the system return to the initial position shown in FIG. 1.

We claim:

I. An apparatus for feeding sheets from beneath a pile of sheets, said apparatus comprising a plate for carrying said pile, a rocking middle sucker having a suction nozzle which is hollowed out at its top and which is adapted to contact the bottom sheet of the pile, whereby said bottom sheet is engaged approximately in the middle and near its front edge projecting beyond the plate, a suction air pipe, means connecting said sucker to said suction air pipe and periodically supplying suction to said sucker and then ending this supply of suction, a rocking tongue, said tongue rocking in time with the sucker and being adapted to penetrate between the bottom sheet drawn by the sucker and the next sheet of the pile, rocking pile supports consisting of blower nozzles and located laterally beside said sucker and said tongue, rotating feed segments for drawing the bottom sheet brought by the sucker, two additional rocking side suckers located on opposite sides of said middle sucker and rocking in time therewith, said side suckers being adapted to engage beneath the bottom sheet, and a separate control member connected with said side suckers and a suction air supply for supplying suction to said side suckers with a time delay relatively to the start of suction of said middle sucker and terminating the supply of suction to said side suckers simultaneously with the termination of the supply of suction to said middle sucker.

2. An apparatus in accordance with claim 1, comprising a stationary blower nozzle associated with said middle sucker.

3. An apparatus in accordance with claim 2, wherein said control member is connected with said stationary blower nozzle for controlling both the suction air of said side suckers and the blowing air of said stationary blower nozzle.

4. An apparatus in accordance with claim 3, wherein said control member constitutes a rotary valve and comprises a rotary middle part and two stationary side parts located on opposite sides of said middle part, each of said side parts having two separate arcuate air ducts, said middle part having an aperture for intermittently connecting said air ducts. 

1. An apparatus for feeding sheets from beneath a pile of sheets, said apparatus comprising a plate for carrying said pile, a rocking middle sucker having a suction nozzle which is hollowed out at its top and which is adapted to contact the bottom sheet of the pile, whereby said bottom sheet is engaged approximately in the middle and near its front edge projecting beyond the plate, a suction air pipe, means connecting said sucker to said suction air pipe and periodically supplying suction to said sucker and then ending this supply of suction, a rocking tongue, said tongue rocking in time with the sucker and being adapted to penetrate between the bottom sheet drawn by the sucker and the next sheet of the pile, rocking pile supports consisting of blower nozzles and located laterally beside said sucker and said tongue, rotating feed segments for drawing the bottom sheet brought by the sucker, two additional rocking side suckers located on opposite sides of said middle sucker and rocking in time therewith, said side suckers being adapted to engage beneath the bottom sheet, and a separate control member connected with said side suckers and a suction air supply for supplying suction to said side suckers with a time delay relatively to the start of suction of said middle sucker and terminating the supply of suction to said side suckers simultaneously with the termination of the supply of suction to said middle sucker.
 2. An apparatus in accordance with claim 1, comprising a stationary blower nozzle associated with said middle sucker.
 3. An apparatus in accordance with claim 2, wherein said control member is connecteD with said stationary blower nozzle for controlling both the suction air of said side suckers and the blowing air of said stationary blower nozzle.
 4. An apparatus in accordance with claim 3, wherein said control member constitutes a rotary valve and comprises a rotary middle part and two stationary side parts located on opposite sides of said middle part, each of said side parts having two separate arcuate air ducts, said middle part having an aperture for intermittently connecting said air ducts. 